Considerable work has been done in the field of rigid containers having removable bladder-type linings. Typically, such linings include both one and two spout linings, and linings replaced through a container opening are known in the art.
Beckman U.S. Pat. No. 3,198,390 discloses a milk container having an outer rigid housing and a replaceable inner bladder, where the single neck bladder is replaced via the spout opening in the housing without disassembly of the housing. The opposite end of the bladder is not attached to the housing cavity to prevent the bladder from collapsing and blocking the spout.
Bonerb U.S. Pat. No. 4,658,989 discloses a disposable, flexible liner having upper and lower necks which pass through respective openings in an outer rigid container, and pressure sensitive adhesive spots to cause the lining to adhere to the container. However, Bonerb does not show any particular spout assembly to secure the necks of the bladder to the container.
Barr U.S. Pat. No. 3,834,570 Goss U.S. Pat. No. 3,453,033, Robbins U.S. Pat. No. 4,805,799, Silveyra U.S. Pat. No. 2,338,604, Croley U.S. Pat. No. 4,516,692, Vom Hofe U.S. Pat. No. 4,560,085, and Instead U.S. Pat. No. 3,082,924 all disclose container systems using an outer rigid container and an inner bladder having a single neck used to dispense liquids from the container.
Jones U.S. Pat. No. 4,635,814 discloses a lined drum having a pair of spouts included in a bladder. However, it is clear that the container must be disassembled to remove and replace the bladder. The same appears to be true for the lined tank shown in Downs U.S. Pat. No. 2,794,570. Fell U.S. Pat. No. 4,461,402 and Nittel U.S. Pat. No. 4,586,028 also show rigid containers with removable bladders having two openings. However, it appears that in Fell the bladder is not inserted into the housing via a spout opening, and in Nittel the bladder has only a single spout secured to the container.
The background art does not describe a substantially rigid, single opening container having a bladder, where the bladder neck is secured to the opening and the other end of the bladder is secured to the inside of the container cavity at a point spaced from the opening. This prevents the bladder from collapsing on itself and clogging material flow from the opening. Further, the bladder is replaceable via the opening without disassembly of the container.
Still further, the art does not describe a substantially rigid, two opening container having a bladder where the neck of the bladder is secured to the one opening and where the bladder is replaceable via one of the openings without disassembly of the container.